thomas



Feb. 2 1926. Re. 16,257

J. G. P. THOMAS CLUTCH AND BRAKE CONTROL ON ROAD VEHICLES Original Filed t 9. 1920 /g m. u

L9 gave/nick Jfl/v 600mm 595m moms @515 1115 61am 'Re issued Feb. 2, 925. I f Re. 1(13257;

UNITED STATES PATENT- OFFICE;

JOHN GODFREY PARRY THOMAS, OI" PRESTON, ENGLAND, ASS IG NOR '.'I.O' GENERAL- MOTORS CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

r cno'rcir AND Banks CONTROL on ROAD VEHICLES.

Original No. 1,441,545, dated January 9, 1923, Serial No..417,859, filed October 19, 1920. Application for reissue filed April 12, 1924. Serial No. 706,198. 4

' To all whom it may concern: I which is guided upon the piston rod and can Be it known that I, J OI-IN GODFREY PARRY be depressed relatively to it against the ac- THOMAS, a subject-of the King of Great tion of a spring. Any such depression per-. Britain and Ireland, residing at 5 Lathom mits the opening of a valve under spring or 5 Street, Preston, Lancashire, England, have fluid pressure, by which the interior of the invented certain new and useful Improvecylinder is connected with the suctionpipe; ments in Clutches and Brake Controls on andia suiiicient depression of the pedal rela- Road Vehicles, of which the following is a tive to the piston rod closes a valve or port full, clear, concise, and exact description,- through which the interior of the cylinder such'aswill enable others skilled in the art" is open to the atmosphere. The piston rod v to which the invention relates to make and is interconnected with the brake lever or use the same, reference being made therein other brake-operating medium so that its to the accompanying drawings, which form movement, whether under the pressure on a part of this specification. the piston or the pressure on the pedal, or 15 This invention relates to the operation both, will cause the application of the brake. and control ofthe brakes and clutches of- Further details of this preferred construcmotor road vehicles. It consists in an aption may be seen from the accompanying paratus which enables the brake to be apdrawing which shows it diagrammatically plied or the clutch to be engaged by power, in longitudinal section.

20 the extent of application or engagement be In this. figure 1 is the pedal, the stem of mg controlled by a pedal or handle of usual which slides within the end of the hollow form; while in the event of the failure of piston rod 3 against the action of a spring the power the pedal or handle serves ,for 4: interposed between the stem 2 and a shoul- 'the application of the brake or clutch by der in the piston rod. The power cylinder 25 foot or hand in the usual manner. is indicated at '5 and its piston at 6. 'I he The invention'is hereinafter described in brake lever 7 has a forked end in position In its application to a pedal controlled brake; to be engaged by a collar 8 secured upon the substitution of a handle for the pedal, or the piston rod which is guided in a gland the application of the invention to a clutch 9 and bracket 10 or in other suitable fashion.

instead of to a brake, will need no separate It will be apparent that the brake lever explanation, the word pedal being read as 7 will be operated upon movement of these including handle and brake as including piston rod 3, whether such movement reclutch.- sults merely from depression of the pedal In order that the degree of application after the spring is compressed, or from 35 of the brake may be controlled by the pedal movement ofthe piston 6. As usual the the power is arranged to be applied upon debrake lever is lifted or the. brake pressed pression of the pedal, and to be cut oil? upon into off position by a suitable spring, not the consequent movement of the brake ocshown. curring; or in other words the, admission There is attached tothe stem 2 of the 40 of power is dependent on relative or non-t pedala tubular prolongation 11 which excorresponding movement of the pedal and tends completely throu 'h the piston rod brake, that is to say, upon movement of one and piston, and at its end beyond the piston member which is notaccompanied by corcarries a screw cap 12 which attaches to responding movement of the other. "it the enlar ed head 13 of a rod 14. This ('5 As a prime mover, a device operated by head is s all enough to pass freely into fluid power may be used, a convenient source the tube 1, so that it 's not of necessity being the suction pipe of the internal compushe down" when the pedal is depressed, bustion engine by which the-road vehicle is but/1s positively pulled up when the cap propelled, for even when the engine is only 12 engages it. In the stem 2 there is formed 50 turning over light a vacuum of eigh' to ten :1 port 15, and this ported stem, co-operating pounds is available in this pipe. In a prewith the hollow piston rod '3, constitutes a 1 ferred construction apower cylinder ope'rvalve which is closed by a sufiicient dcpresatcd, from this source is arranged with its sion of the pedal 1 relatively to the piston axis in the line of movement of the pedal, rod. Through this port 15 and through a similar port 16 in the tube 11 and through the tube itself the interior of the cylinder is normally connected with the atmosphere.

, The rod 14 is attached to and operates a piston valve consisting of a piston 17 movmg in a small cylinder 18. Thispiston may normally be pressed downward by a spring; but in the construction shown the lower end of the cylinder is permanently connected with the suction pipe of the engine through a pipe 19, so that the suction continually exerted on the piston 17\ suffices to pull it down when the cap 12 permits. Vhensufficiently lowered the piston. 17 uncovers a port 20 connected through pipe 21 with the suction pipe of the engine.

The operation of the apparatus is as follows: Initial pressure upon the pedal 1 moves it downwardrelatively to the piston 3, compressing the spring 4, that spring being weaker than the spring which holds the brake ofl'. Such movement permits the piston 17 to move downwards and to uncover the port The interior of cylinder 5 is then connected with the suction pipe of the engine,'but as it is still also connected with the atmosphere through the port 15, air is at first idly drawn through that port and thetube 11, and the brake is been sufficiently depressed to bring the port 15 wholly within the piston rod 3, and thereby close it, the suction exerted on the piston 6 pulls it down and through thecollar 8 and lever7 applies the brake. If the pedal 1 is not further depressed the movement of the piston rod 3 will uncover the port 15, whereupon such movement will stop. If the pedal 1 is further depressed the brake lever 7 must move further before the port 15 7 "can again be uncovered. Thus the extent of depression of the pedal governs the extent of application of the brake.

Nevertheless, if for any reason, as through the engine"-stopping, power should fail, the' depression of the pedal Wlll obviously, after the spring 4 is compressed, itself cause movement of the pistoh rod and therefore of the brakelever 7 under the pressure of the foot. Moreover, if" the power applied to the piston is not alone suilicient, as when the engine suction is low or if the piston is not large enough, there will be concurrent manual and power operation, port 15 remaining covered.

While .I have shown a suction cylinder and piston as-the prime mover, and while certain phases of the invention relate to mechanism suitable for use therewith, the

invention in other phases is equally applica--' the invention relates to the interconnection of the brake pedal with the parts of this transmission between the prime mover and the device which it operates, especially where a preliminary lost motion of the pedal oper- T0 ates means such as a valve controlling the prime mover, equivalent operating media of various kinds are intended to be covered by the claims where they are not specifically limited. Accordingly it is my intention that the 'scope'of the invention be limited only by the terms and language of the appended claims. 1

I claim:

1. 'In a motor road vehicle having an in- B0 ternal combustion engine the combination with a control lever, of a cylinder and piston adapted to operate said lever, a control device operable by the driver, a connection.

between said cylinder and the suction pipe i ,necting saidcylinder with the suction pipe 95 not operated. But when the pedal 1 has of the engine, a connection between said s-valve and 'said control device normally holdand means causing said valve to open when so permitted.

3: In a motor roadvehicle the combination of a. control lever with a' cylinder, piston and piston rod adapted to operate said lover, a control pedal operable by the driver mounted on and slidablc along said piston rod to a limited extent, a spring resisting movement of said pedal along said rod, and means admitting power to said cylinder adapted to be actuated by said pedal.

4. In a motor road vehicle, the combination of a control lever, a control device actuated by the driver, a yielding connection between said device and said lever permitting limited movement of said device without movement of said lever, and a power apparatus for actuating said lever governed by motion of said control device which strains said yielding connection.

5. In a motor road vehicle having-an internal combustion engine, the combination with a control lever of a power cylinder opera-ting said lover a valve connecting said cylinder with the suction pipe of the engine, and a control device actuated by the driver fol-governing said valve, the'control device being connected to operatethe lever directly" if the power of said cylinder is not suflicient.

6. In a motor road vehicle having an internal combustion engine, a power unit for rternal combustion engine, the combination of a control lever with a cylinder, piston ton adapted to operate said lever, a control device operable by the driver, a yielding connection between said device and said lever, permitting the lever to be operated by said device after limited independent movement of the device, a valve connecting said cylinder with the suction pipe of the engine, and a second valve closed by movement of the control device not accompanied by movement of the" lever connecting said cylinder with the atmosphere.

8. In a motor road vehicle having an inand hollow piston rod adapted to operate said lever. a control pedal operable by the driver mounted on and slidable along said piston rod and forming therewith a valve connecting said cylinder with the atmos phere. and means connecting said cylinder -with the suction pipe of the engine.

9. In a motor road vehicle the combina tion with a control lever. of a control device for actuation by the driver, a yieldingconnection between said device and said lever permitting the lever to be operated by said device after limited independent movement of the device, a power apparatus for. actuating said lever. and means admitting power to said apparatus depending on the position of both said lever and said control device.

10. In a motor road vehicle having an internal combustion engine. the combination with a control medium. of a cylinder and piston adapted to operate said medium. a control :device operable bv the driver. a connection between said cylinder and the suction pipe of the engine, and a valve connecting said cylinder with the atmospheredepending both on the position of said control device and on the relative positions of the cylinder and piston.

11. In a motor road vehicle having an internal combustion engine. the combination of a control medium with a cylinder'and piston adapted to operate said medium. a

control device operable by the driver, a valveconnecting said cylinder with the suction pipe of the engine, a connection between said valve and said control device. normally holding said valve closed but permitting it to open upon actuation of said control device. and means causing said valve to open when so permitted.

12. In 'a motor road vehicle having an internal combustion engine, the combination of a control medium with a cylinder and piston adapted to operate said medium, a control device operable by the driver, a valve connecting said cylinder with a source of fluid power, a connection between said valve and said control device normally. holding said valve closed but permitting it to open upon actuation of said control device, and means causing said valve to open when so permitted.

13. In a motor road vehicle. in combination. a brake-applying medium. fluid power means for operating said medium. avalve controlling said fluid power means, a brake. pedal arranged to operate the valve and also arranged to operate said medium' directly. and mechanismwhereby both said fluid power means and said brake pedal may act upon said brake applying medium at one and the. same time.

14.. In a motor road vehicle. in combina tion. abrake-applying medium. fluid power means for operating said medium, a valve controlling said fluid power means. and a brake pedal arranged to open the valve and to operate said medium di'rectly,'the valve and pedal being arranged to permitboth manual and fluid power to be applied to the brake-applying medium at the same time.

15. In a motor road vehicle, in combina tion. a brake-applying lever, fluid power means foroperatingthe lever, a valve controlling said fluid power means and a. brakepedal arranged to operate the valve and directly to engage the brake-applying lever to apply additional power thereto manually.

16. In a motor road vehicle having an internal combustion engine, the combination with a brake-applying lever. of a cylinder and piston for operating the lever, a valve connecting the cylinder with the suction pipe of the-engine, a brake pedal arranged to operate the valve and directly to engage the brake-applying lever to apply manual power thereto, and mechanism whereby both said piston and said brake pedal may act uponsaid brake applying lever at one and the same time.

17. In a motor road vehicle having an internal combustion engine the combination. with a brake-applying medium. of a cylinder and piston for operating said medium, a valve connecting said cylinder to the suction pipe of the engine. and a valve-controlling pedal operable by the driver, the extent of depression of the pedal governing the extent of application of the'brake.

18. In a motor road vehicle having an internal combustion engine the combination, with a brake-applying medium, of a cylinder and piston for operating said medium.

4 a valve connecting said cylinder to the sue tion pipe of the engine, and a valve-controlling pedal operable by the driver, the extent of depression of the pedal governing the amount of power applied to said medium.

19, In a motor road vehicle having an internal combustion engine, the combination with, a control medium, of a device operated .by the power of the engine and connected to the control medium, and a manually-operated member arranged between the power device and the control medium to operate the control medium manually and also arranged to control the power device to provide manually-controlled power operation of the control medium.

20. In a motor road vehicle having an internal combustion engine, the combination witha control medium, of a fluid-power cylinder and piston operated by power derived from the engine through the agency of a power fluid, a transmission from the cylinder and piston to the control medium, a manually-operated member connected in said transmission between the cylinder and piston and the control medium, and a valve controlling the flow of power fluid to and from said cylinder and which is operated by said member.

21. The combination'of a device to be actuated, with fluid-pressure power means, a force transmission between said device and means, a pedal having lost-motion connection with said transmission, and a valve controlling said fluid-pressure means and which is operated by lost-motion movement of the pedal in such a manner that manual operampm tion of said device beginsafter the valve is fullyhpen.

22. A motor vehicle comprising in combination, vehicle-controlling mechanism, a primemover, a manually-operated member movable in unison with the moving member of the prime mover, a force transmission between the prime mover and the vehicle-controlling mechanism, means for controlling energization of the prime mover, a device moved by the manually-operated member but capable of movement with respect thereto, a connection from said device operating said means in response to relative movement between said device and the manually-operated member, and means urging the device to its inoperative position with respect to the manually-operated member.

23. The combination of a device to be actuated with a prime mover-and a manuallyoperated member movable in unison with a moving member of the prime mover, together with a force transmission between the prime mover and said device,-mea-ns for controlling the energization of the prime mover, and a control device yieldingly moved by the manually-operated member and arranged to operate said means by resistance to its yielding movement so that the prime moveris not energized when the control device is in its initial position with re spect to the manually-operated member and is energized when the control device yields with respect to the manually-operated memher.

In testimony whereof I aflix my signature.

I J G. P. THOMAS. 

